JP2003130733A - Temperature history indicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a handy indicator that has improved durability such as water resistance, oil resistance, and light resistance, and stability, and can accurately display whether a specific temperature history is experienced or not by the change in irreversible, clear color tone. SOLUTION: In the temperature history indicator, a thermally sensitive discoloration layer including a granular or powder-like heat-meltable substance having a melt point equivalent to a temperature to be recorded, a granular or powder- like coloring matter that is dispersed or dissolved into the heat-meltable substance for diffusion, and an ink vehicle where the heat-meltable substance is dispersed is attached to a substrate and is covered with a photo-setting resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can record whether a temperature history exceeds a predetermined temperature by a change in color tone, durability,
The present invention relates to a temperature history indicator having excellent stability.

[0002]

2. Description of the Related Art There are products such as processed foods which must be heated above a predetermined temperature during production. In addition, there are products such as pharmaceutical products and food products that are deteriorated, decomposed, or decomposed when they exceed a predetermined temperature during distribution or storage. There are products such as electric equipment and electric parts that may be damaged or damaged or cause a fire due to overheating during use like a motor.

In order to detect whether or not a product has passed a temperature history exceeding a predetermined temperature, an indicator showing a change in color tone due to heat is used.

Generally, in order to improve the durability and stability of labels and printed materials, film laminating and printing of a coating agent are carried out.

As a method of improving the durability and stability of this indicator whose color tone changes due to heat, there is a method of applying no heat such as coating with an adhesive layer-containing film. There is a risk of stains, resulting in discoloration or peeling of the indicator, regardless of heat. There is also a method of printing a coating agent containing a solvent on the upper surface of this indicator, but if the hot air is blown to dry the solvent, the color tone will change due to the heat, so heat such as blowing cold air will be applied. Since it has to be dried without spending it, much time and equipment are wasted.

Therefore, there has been a demand for a temperature history indicator which has durability and stability and can be manufactured efficiently.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is excellent in durability such as water resistance, oil resistance, light resistance and stability and has passed a predetermined temperature history. It is an object of the present invention to provide a simple indicator that can accurately display an irreversible and clear change in color tone.

[0008]

The temperature history indicator of the present invention, which has been made to achieve the above object, comprises a granular or powdery heat-melting substance having a melting point corresponding to the temperature to be recorded, and a heat-melting substance. A thermosensitive color-changing layer containing a granular or powdery pigment dispersed or dissolved in the substance and diffused therein, and an ink vehicle in which the substance melted by heat is diffused is applied to a substrate and coated with a photocurable resin. It is said to have been done.

The photo-curable resin is a silicone resin, an epoxy resin, an amino resin, a urethane resin, a urethane acrylate resin, an ether resin, an epoxy acrylate resin, an ether acrylate resin, an alkyd resin, a vinyl acetal. The resin is preferably an acrylic resin, an acrylic polyester resin, or an acrylic resin.

The photocurable resin may be one which is polymerized or crosslinked by irradiation with active energy rays and cured.

More specifically, the photocurable resin is DICURE AK (trade name of Dainippon Ink and Chemicals, Inc.), F
DS New (trade name of Toyo Ink Mfg. Co., Ltd.), Lake Cure TU4400 (trade name of Jujo Chemical Co., Ltd.), U
VSPA clear (trade name of Teikoku Ink Mfg. Co., Ltd.),
A commercially available active energy ray-polymerizable monomer-containing composition such as UV8418 (trade name, manufactured by Seiko Advance Co., Ltd.) is printed, applied or sprayed on the temperature-sensitive color changing layer attached to the substrate to produce an active energy ray. For example, it is formed by irradiating ultraviolet rays, infrared rays, electron beams, or radiation to rapidly polymerize and cure it into a thin film or a lump that is transparent or semitransparent.

The photocurable resin covers the temperature-sensitive discoloration layer to make it less susceptible to water, oil, light and the like.

The heat-fusible substance is a component that determines the discoloration temperature, has a melting point at a temperature to be recorded under normal pressure, and is heated to a temperature higher than the melting point to be melted by heat to be in the form of particles or powder. It is a substance that changes into.

The dye is contained in the temperature-sensitive color changing layer in the form of particles or powder, and diffuses by being dispersed or dissolved in a heat-meltable substance which is heat-melted. Further, the dye may be one in which the particle surface or powder surface of the dye is wetted by this heat-melted substance.

The ink vehicle does not dissolve or diffuse the heat-meltable substance and the dye at room temperature, but can diffuse the heat-melted heat-meltable substance in which the dye is dispersed or dissolved. is there.

The temperature history indicator is used by being placed in the vicinity of the product whose temperature history is to be detected or attached to the product. The indicator may be a product in which a temperature-sensitive discoloration layer is directly applied and coated with a photocurable resin.

Before heating the temperature history indicator,
The granular or powdery heat fusible substance and the granular or powdery pigment are in a mixed state, and the pigment is covered with the thermofusible substance. When the indicator is heated above the melting point of the hot melt material, the hot melt material melts. When the dye is dispersed or dissolved in the heat-melted substance to diffuse, or the granular or powdery surface of the dye is wetted with the heat-melted substance, the thermochromic layer is distinctly changed in color. By observing this discoloration through a transparent or translucent photocurable resin and visually observing a change in the color tone of the indicator, it is confirmed that a predetermined temperature history has been passed.

The photocurable resin of the temperature history indicator is obtained from an active energy ray-polymerizable monomer composition containing no organic solvent, and is polymerized by irradiating with an active energy ray to instantly cure. To do. Therefore, in manufacturing the indicator, time and equipment can be efficiently used.

Since the photocurable resin forms a film-shaped resin, it does not hinder the discoloration of the temperature-sensitive discoloration layer. Therefore, the color history of the temperature history indicator changes clearly. Furthermore, it has excellent stability in water resistance, oil resistance, light resistance and oxidation resistance during storage and use.

Since the diffusion of the dye into the heat-fusible substance is irreversible, this indicator does not return to the color tone before the change even when the temperature drops after the color tone changes and the heat-fusible substance solidifies. .

[0021]

EXAMPLES Examples of the temperature history indicator of the present invention will be described in detail below.

The temperature history indicator has a temperature-sensitive discoloration layer,
It is attached to a base material and coated with a photocurable resin.

The temperature-sensitive color changing layer is printed with a temperature-sensitive ink containing a heat-fusible substance, a dye, and an ink vehicle. The photo-curable resin is a composition in which an ultraviolet-polymerizable monomer-containing composition printed by covering the temperature-sensitive color changing layer is polymerized and cured by irradiation with ultraviolet rays.

The temperature history indicator is manufactured as follows.

First, a thermosensitive ink is prepared by uniformly kneading a heat-fusible substance and a pigment crushed to a desired particle diameter with an ink vehicle with a kneader.

The heat-fusible substance in the temperature-sensitive ink is 0.01
It preferably has a diameter of μm to 5 mm. It is preferable that the heat-sensitive ink contains 10 to 70% by weight of the heat-meltable substance. If it is less than 10% by weight, the change in color tone is unclear, while if it is more than 70% by weight, the adhesive strength is lowered and coating or printing on the substrate is impossible.

Specific examples of the heat-fusible substance include myristic acid, palmitic acid, adipic acid, octanoic acid, tricosanoic acid, tetratriacontanoic acid, 2,3-dimethylnonanoic acid, 23-methyltetracosanoic acid, 2- Hexenoic acid,
Brassic acid, 2-methyl-2-dodecenoic acid, β-eleostearic acid, behenolic acid, cis-9,10-methyleneoctadecanoic acid, shoalmoogric acid, 3,3 ′.
-N-dodecyl thiodipropionate, trilaurin,
Palmitic acid anilide, stearic acid amide, zinc stearate, salicylic acid anilide, N-acetyl-L-glutamic acid, caproic acid-β-naphthylamide, enanthic acid phenylhydrazide, arachidic acid-p-chlorphenacyl, cholesteryl formate, 1-aceto-. 2,3-Distearin, thiolauric acid-n-pentadecyl, stearic acid chloride, palmitic acid, stearic acid-acetic anhydride, succinic acid, sebacic acid benzyl ammonium salt, 2-bromovaleric acid, methyl α-sulfostearate Fatty acid derivatives such as sodium salt and 2-fluoroarachidic acid; octadecyl alcohol, cholesterin,
D-mannitol, galactitol, heptatriacontanol, hexadecan-2-ol, 1-trans-
2-octadecenol, β-eleostearyl alcohol, cycloeicosanol, d (+) cellobiose,
p, p'-biphenol, riboflavin, 4-chloro-
Alcohol derivatives such as 2-methylphenol and 2-bromo-1-indanol; dihexadecyl ether, dioctadecyl ether, cytidine, adenosine,
Ether derivatives such as sodium phenoxyacetate, 1,3-bis (4-hydroxyphenoxy) benzene, aluminum triethoxide; stearaldehyde, paralauryl aldehyde, parastearic aldehyde, naphthaldehyde, p-chlorobenzaldehyde,
Aldehyde derivatives such as phthalaldehyde and 4-nitrobenzaldehyde; stearone, docosane-2-
Ketone derivatives such as on, phenylheptadecyl ketone, cyclononadecane, vinylheptadecyl ketone, 4,4-bisdimethylaminobenzophenone, bis (2,4-pentanedionite) calcium, 1-chloroanthraquinone; tricosylamine, dioctadecyl Amine derivatives including amine, N, N-dimethyloctylamine, heptadecamethyleneimine, naphthylamine, ethyl p-aminobenzoate, o-trithiourea, sulfamethazine, guanidine nitrate, p-chloroaniline, propylamine hydrochloride; hexyl. Amide, octacosylamide, N-methyldodecylamide, N-methylheptacosylamide, α-cyanoacetamide, salicylamide, dicyandiamide, 2-nitrobenzamide,
Amide derivatives including N-bromoacetamide; pentadecane nitrile, margaronitrile, 2-naphthonitrile, o-nitrophenoxyacetic acid, 3-bromobenzonitrile, 3-cyanopyridine, nitrile derivatives including 4-cyanophenol; hexadecane , 1-nonatriacontene, trans-n-2-octadecene,
Hexatriacontylbenzene, 2-methylnaphthalene, bisene, cyanuric chloride, 1-fluorononadecane,
1-chloroeicosane, 1-iodopentadecane, 1-
Hydrocarbon derivatives such as bromoheptadecane and 1,2,4,5-tetrakis (bromomethyl) benzene; pentadecanethiol, eicosanethiol, 2-naphthalenethiol, 2-mercaptoethylether, 2-nitrobenzenesulfenyl chloride. Derived thiol derivative; 1,3-diatine, 2,11-dithia [3,
3] At least one kind of sulfide derivative including paracyclophane, bis (4-hydroxy-3-methylphenyl) sulfide, 4,4-dipyridyl sulfide, and 4-methylmercaptophenol is used.

The dye contained in the temperature-sensitive ink is from 0.001 μm to
It preferably has a diameter of 5 mm. In the temperature-sensitive color changing layer, it is preferable that the dye is contained in a ratio of 0.001 to 100 parts by weight with respect to 100 parts by weight of the heat-fusible substance.

Specific examples of the dye include CI Direct
Orange 39, CI Direct Brown 2, CI
Acid Yellow 73, CI Acid Red 5
2, CI Acid Violet 49, CI Basic Yellow 11, CI Basic Red 38,
Cation Red SGLH, Cation Red GTL
H, Cation Red 4GH, Cation Red 7BN
H (manufactured by Hodogaya Chemical Co., Ltd.), C.I.Moldant Red 7, C.I.Moldant Black 38, C.I.Azoic Blue 9, C.I.Azoic Diazo Component 11, C.I. Sulfur Black 1, CI Sulfur Red 5, CI Bat Green 9, CI
Bat Violet 2, CI Disperse Blue 3, Discharge Red BB (manufactured by Mitsui Toatsu Dyestuffs Co., Ltd.), CI Reactive Blue 19, CI Reactive Blue 15, Remazol Br Blue R-KN
(Manufactured by Mitsubishi), CI Solvent Orange 2, CI
Solvent Blue 25, CI Acid Green 1, Flavianic Azido Disodium Salt,
Dyes that include primulin sulfonic acid; 4,10-dibromoanthanthrone, dibenzoanthrone, cochineal lake, CI pigment yellow 1, CI pigment red 38, CI pigment blue 1
5, CI Pigment Red 209, CI Pigment Yellow 109, CI Pigment Green 1
0, CI Basic Red 1-rake, CI Acid Red 87-rake, CI Pigment Blue 6, CI Pigment Red 179, CI Pigment Red 88 , Alizarin Lake, CI Pigment Violet 23, CI Pigment Green 8,
Organic pigments such as CI pigment red 53, CI pigment yellow 23-lake, tannic acid / gallic acid / iron lake, CI pigment yellow 34, and CI pigment yellow 35. Inorganic pigments such as kaolin, dark blue, strontium sulfate, titanium dioxide, aluminum hydroxide, calcium silicate, and carbon black are used. You may use these dyes in mixture of 2 or more types. The C.I. is an abbreviation for color index.

As the ink vehicle in the temperature-sensitive ink, for example, acrylic resin, phenol resin, nylon, ethyl cellulose, hydroxymethyl cellulose, polyvinyl alcohol, carboxymethyl cellulose are used. More specifically, PAS8, which is a commercially available ink vehicle.
Examples include 00 medium (trade name of Jujo Kako Co., Ltd.) and high set mat medium (trade name of Mino Group).

The ink vehicle is a silicone resin, an epoxy resin, an amino resin, a urethane resin,
Urethane acrylate resin, ether resin, epoxy acrylate resin, ether acrylate resin,
A photocurable resin of any one of an alkyd resin, a vinyl acetal resin, an acrylic polyester resin, and an acrylic resin may be used. More specifically, commercially available vehicles such as Dicure AK (manufactured by Dainippon Ink and Chemicals, Inc.) and FDS New (Toyo Ink Mfg. Co., Ltd.)
Made), Reycure TU4400 (Jujo Chemical Co., Ltd.)
Made), UVSPA clear (Teikoku Ink Mfg. Co., Ltd.)
Manufactured by Seiko Advance Co., Ltd.).

The temperature-sensitive ink may contain a solvent which does not dissolve the heat-fusible substance and the dye but dissolves the ink vehicle. Examples of such a solvent include water, ethanol, butanol, ethyl acetate, isoamyl acetate, methyl ethyl ketone, methyl isobutyl ketone, xylene, diethylbenzene, toluene, butyl cellosolve, ethyl cellosolve, and mineral spirit.

Further, the temperature-sensitive ink may contain a dispersant exemplified by talc, magnesium carbonate and silica so that the change in color tone becomes clear by dispersing the dye. The temperature-sensitive ink is exemplified by direct dyes, acid dyes, basic dyes, disperse dyes, reactive dyes, oil-soluble dyes, architectural dyes, mordant dyes, azoic dyes, and sulfur dyes in order to amplify the change in color tone. It may be a dye, an organic pigment or an inorganic pigment, and may contain an auxiliary colorant having a color showing a color tone and a contrasting color of the dye. Further, the temperature-sensitive ink may contain a wax or a surfactant that adjusts the fluidity and the drying property of the ink.

Next, this temperature-sensitive ink is printed on a substrate to form a temperature-sensitive discoloration layer, and an ultraviolet-polymerizable monomer-containing composition is applied thereon by printing, and ultraviolet rays are irradiated to form a thin film photocurable resin. Once formed, a temperature history indicator is obtained.

Examples of the base material include plain paper, Japanese paper, and Kent paper; synthetic paper; wood exemplified by cypress; polypropylene, polyethylene terephthalate, acrylonitrile-butadiene-styrene resin, polycarbonate, acrylic resin. A plastic one is used.

Printing of the temperature-sensitive ink and printing of the composition containing an ultraviolet-polymerizable monomer are carried out, for example, by screen printing, offset printing, gravure printing, brush coating.

This temperature history indicator is in the form of a card,
It may be in the form of a sheet or a rod, or may be a label having an adhesive layer on the back surface.

An example in which a temperature history indicator to which the present invention is applied is manufactured as a prototype is shown in Example 1, and an example in which an indicator to which the present invention is not applied is manufactured as a comparative example.

(Example 1) 100 parts by weight of myristic acid, which is a heat-melting substance, and Acid Yellow 73, which is a pigment.
0.1 part by weight of ethyl cellulose, 8 parts by weight of ethyl cellulose as an ink vehicle, and diethylbenzene 200 as a solvent.
White parts of the temperature-sensitive ink were prepared by mixing 1 part by weight and kneading with a kneader until uniform. This was screen-printed on the surface of a plastic synthetic paper as a base material to form a white thermosensitive discoloration layer. Next, FD is applied to this temperature-sensitive discoloration layer.
Apply S New (trade name of Toyo Ink Mfg. Co., Ltd.),
Upon irradiation with ultraviolet light, a temperature history indicator was obtained, which was coated with a photocurable resin that was polymerized and cured.
Even if you attach this indicator to a curved surface and soak it in oil,
No change in the color tone of the thermosensitive color change layer was observed. In addition, the manufacturing time can be shortened and the product can be efficiently produced. When this indicator was exposed to 50 ° C. or higher, its color tone changed to yellow clearly, and it did not return to the original color tone after cooling.

Comparative Example 1 An indicator was obtained in the same manner as in Example 1 except that a polyethylene terephthalate laminate film with an adhesive layer was attached instead of the photocurable resin. When it was attached to a curved surface and immersed in oil, the oil penetrated the adhesive layer, causing the temperature-sensitive discoloration layer to discolor. Even when this indicator was exposed to 50 ° C. or higher, no further change in color tone was observed.

[0041]

As described above in detail, in the temperature history indicator of the present invention, the change in color tone when the temperature exceeds a predetermined temperature is irreversible and clear, and the color tone after the color change can be stored as it is. it can. This indicator indicates that the product has exceeded the specified temperature when confirming that it has been heated above the specified temperature in the heating process of manufacturing products such as processed foods, and during the distribution and storage of products such as pharmaceuticals and foods that should avoid heating. It is preferably used for confirming that there is no malfunction, predicting failure due to overheating during use of products such as electric parts, and confirming safety.

Since this indicator is coated with a photo-curing resin, it adheres to water or edible oil used in the production of processed foods, adheres water that condenses during low-temperature storage of pharmaceuticals, and food products. Even if the product is exposed to sunlight during distribution or storage, the change in color tone is not affected and the thermosensitive discoloration layer does not elute, which is hygienic.

This indicator has high productivity because it can be manufactured easily.

Claims (3)

[Claims] 1. A particulate or powdery heat-fusible substance having a melting point corresponding to a temperature to be recorded, a particulate or powdery pigment dispersed or dissolved in the heat-melted substance to diffuse, and heat-melted. An irreversible temperature history indicator characterized in that a temperature-sensitive discoloration layer containing an ink vehicle in which the substance diffuses is attached to a substrate and coated with a photocurable resin. 2. The photocurable resin is a silicone resin, an epoxy resin, an amino resin, a urethane resin,
Urethane acrylate resin, ether resin, epoxy acrylate resin, ether acrylate resin,
The temperature history indicator according to claim 1, wherein the temperature history indicator is an alkyd resin, a vinyl acetal resin, an acrylic polyester resin, or an acrylic resin. 3. The temperature history indicator according to claim 2, wherein the photocurable resin is formed by being polymerized and cured by irradiation with active energy rays.